Method of making mining machine chains and links therefor



Mmh 28, 1939, F, F LKE 2,152,139

METHOD OF MAKING MINING MACHINE CHAINS- AND LINKS THEREFOR Filed March 27, 1955 2 Sheets-Sheet 1 ATTORNEYS March 28, 1939f LK 2,152,139

METHODYOF MAKING MINING MACHINE CHAINS AND LINKS THEREF OR Filed Mar oh 27, 1935 I 1 2 Shets-Sheet 2 ATTORNEYS Patented Mar. 28, 1939 METHOD OF MAKING MINING MACHINE GHAINS AND LINKS THEREFOR Frank L. Fulke, Terre Haute, llnd., assignor to Frank Prox Company, Terre Haute, Ind., a corporation of Indiana Application March 27, 1935, Serial No. 13,198

Claims.

The present application relates to methods of producing mining chains and links therefor. Primarily, the invention is concerned with the production of mining. chains for various machines having various dimensions, that production to be as efficient as possible.

Further and more specifically stated objects of the invention will appear as the description proceeds.

To the accomplishment of the above and related objects, my invention may result in the production of the forms illustrated in the accompanying drawings, attention being called to the fact, however, that the drawingsare illustrative only, and that change may be made in the specific construction illustrated and described, or in the specific steps stated, so longas the scope of the appended claims is not violated.

Fig. 1 is a more or less diagrammatic plan of a section of a mining machine chain;

Fig- 2 is a diagrammaticcompo-site view of four alternate links of a miningchain constructed in accordance with the present invention, the intermediate links having been omitted from the view for clarity; V

Fig. 3 is a side elevation of a completed link constructed in accordance with theinvention;

Fig. 4 is an end view thereof; v

Fig.5 is a side elevation of a side strap adapted to be associated with such link;

Fig. 6 is an end view thereof;

Fig. 7 is a side elevation of a forged blank from which the link of Figs. 3 and 4 is to be made;

Fig. 8 is an end view thereof;

Fig. 9 is a view similar to Fig. 8, but showing a different form of link, and indicating onemanner of modifying the shape of such a link to adapt the same'to machines of various dimensions; v

Fig. 10 is a View similar to Fig. 9, and indicatinganother manner of modifying the shape of the link to adapt it to machines of various dimensions;

Fig. 11 is a side elevation of a third link-blank shape; I

Fig. 12 is anend view thereof; and

Fig. 13 is a side elevation, partly in section, of a link shape, showing a method of providing a stop abutment for the cutter to be received in the cutter socket;

A mining machine, so called, is a large, preferably automotive, machine' carrying at its front end a forwardlyprojecting arm or trackway upon which is supported'a chain. A driven sprocket is positioned at the inner end of the trackway, and

an idler sprocket is carried at the extremity of the trackway, the chain being mounted to ride on said sprockets.

The chain consists of links, connected to each other by pairs of side straps, each of said links carrying a cutter. As the machine moves forward, the chain, riding over the trackway and the idler sprocket, brings the cutters into contact with the coal to cut a groove in advance of the machine.

It is customary to arrange the cutters of adjacent links of the chain in different planes with respect to the center of the chain, so that the chain will cut a groove of considerable width. This arrangement of the cutters requires the provision of heads on the cutter-carrying links, certain of said heads beingv offset laterally from the center planeof the chain.

. At the present time, there are three major manufacturers of mining machines of this character; and each manufacturer has established a different set of dimensions for his cutter chain trackway. As produced by the machine manufacturers, these machines and their original chains vary also in other respects; viz., link lengths, side strap lengths, diameters of and distances between connecting perforations, and

Widths of kerfs out. In the past, it has been the universal practice of replacement chain manufacturers to reproduce these differences in manufacturing replacement chains for the several machines; but it is a feature of the present invention that I have consolidated all of the variable factors into a set of uniform dimensions, whereby the same links and side straps may be used in the production of a chain for any one of .the ma-' chines, subject only .to variations in link thickness, as described.

I am engaged in the manufacture of cutter chains which I sell as replacements for cutter chains worn out or broken in service on the machines manufactured by other parties.

Heretofore, it has been my practice, and the practice of other manufacturers in the same line of business, to form the links of such replacement chains of castings. As is shown in Fig. 2, it is desirable to have at least four different cutter positions on each side of the central vertical plane of the cutter chain. This has required the provision of eight castings for the links of each chain. Since. the dimensions of the trackways of the three major mining machines vary, it has been necessary to carry in stock different sizes of links to cooperate with the trackways of the respective machines. This has meant that the manufacturer of replacement chains has had to carry in stock twenty-four different shapes of cutter chain links; which has, of course, required large storage space, and a relatively large investment in stock.

I have determined to initiate the use of forged links for my replacement cutter chains; the advantage of the use of such links being obvious.

Because of manufacturing methods, the cost, per piece, of castings in lots of, for instance, fifty is not materially greater than the cost per piece in lots of a thousand. Nor is the cost of patterns used in casting operations particularly high. Therefore, it is not prohibitively extravagant for a manufacturer of replacement chains to carry in stock a suitable number (twenty-five toa hundred or more) of each of twenty-four different link shapes.

But the cost per piece of forgings is very materially affected by the number of pieces produced in each lot. Not only is the cost of producing dies much greater than thecost of producing patterns, but the cost of setting up the dies in the forging machine is very considerable. When that setting-up cost can bedivided among several thousands of pieces produced from one set-up, it does not have too great an effect upon the cost per piece of the group; but its eifect upon the piece cost becomes absolutely prohibitive if fewer than, say, one thousand pieces are produced from 'a single set-up.

It will be readily apparent that theproblem of stocking twenty-four different shapes is verydifferent when the manufacturer must think in terms of thousands rather than in terms of halfhundreds. Therefore, I have been forced to evolve a newmethod of manufacturing mining machine cutter chains and links therefor.

Referring more particularly tothe drawings, it will be seen that the chain, indicated generally at I!) in Fig. 1 of the drawings, is made up of a plurality of links, connected together by side straps. The link HA is provided with a head offset to the right of the center of the chain; and is provided with a cutter-receiving socket I2. The link HA is identical with the link I IA, except that its cutter-receiving socket I 3 is disposed at a different angle to the vertical. The link I I3 is provided with a headofiset'farther to the right, and is formed with a cutter-receiving socket I4. The link H B is identical with the link IIB except that its cutter-receiving socket I5 is disposed at a. different angle to the vertical. I

Between the links HA and HA there is disposed a link IIA whichyin general configuration, is identical with the link 9 IA and is provided With a cutter-receiving socket I2 identical with the cutter-receiving socket of the link IIA; but the link I IA" has been turned end for end with respect to the link IiA before insertion in the chain. Between'the links HA and HE is disposed a link! IB", said linkbeing identical in general configuration with. the link HE and being formed with. a cutter-receiving socket I4 identical with the socket M of the link IIB; but said link HB" has been turned end for end with respect to the link lB before insertion. in the chain. Between the links HE and MB is disposed a link ilB identical ingeneral configuration with the link IIB' andprovided with a cutter-receiving socket I5 identical with the socket I5 .of the link IIB'; but said link 3' has been turned end for end with respect to the link IIB before insertion in the chain. Beyond the link MB is disposed a link I IA' identical in configuration with the link HA and provided with a socket I3 identical with the socket I3 of the link IIA; but the link IIA has been turned end for end with respect to the link IIA before insertion in the chain.

Each pair of adjacent links is connected together by a pair of side straps I 6, I! in a manner later to" be described.

In Fig. '7 is illustrated a link blank IIY. Said 1 blank comprises a head I8, and a main body I9, a base flange 20 projecting laterally from each "side of the' body'l9fand two ears 2I and 22 projecting longitudinally from said body. The lateral thickness 'of- -the flange portion 20 is some- -What greater' th'an the main body portion I9, and the lateral thickness of the ears. 2| and 22 is somewhat less than the thickness of the body portion I9. The lateral dimension of the head I8 is unimportant.

It will be seen that the lateral surfaces of the ears 2I and'22are 'generallycirculanbut that portions 23 and 24 are relieved 'tofacilitate machining. This blank is formedbyforging, the same being a solid block withoutperforations formed therein.

The forgings IIY are formed with lateral thickness dimensionsslig'htly greater than the largest lateral dimensions provided by any mining machine manufacturer. After the blanks have been formed, the ears'arebor'ed toprovide perforations25 and 26 therethrough{ and thereafter-acutter-receivingsocket is formed in each blank.

I have found that the'number cf shapes required for any given'mining machine may be materially reduced by varying the angleat which the cutter-receiving socket is farmed in a single shape. I have found that cutter-receiving sockets may be formed on two' different angles in any given link shape; and that idea isiIIustr-ated-in Fig. 2. I The construction line associated with the cutter I 2X of Fig. 2 represents the-center line of the cutter-receiving socket formed in-links-like the link HA. The construction line associated Withthe'cutter I3X represents the center line of the cutter-receiving socketformed in links like the link HA. The construction line associated with the cutter MX represents thecenter line of the cutter-receiving socket "formed in links like the link I IB. The construction line associated with the cutter I-5X represents the-center line of the cutter-receiving socket formed in links like the link IIB'. V

This method of forming cutter-receiving sockets in links halves the numberof link shapes required-for a given chain.

Each cutter-receiving socket is formed by drilling a hole 27 through the head I8 and body I9-of a linkblank, such hole-extending from the upper surface of the head I8 completely through the body portion. Ihereaften-the opposite sidesof'the bore 27 are longitudinally broached to form rectangular grooves '28 and 2-9.

I then form a bore 30 opening from one end of the head I8 intothe cutter-receiving socket; and said boreSiJisihternally threaded for "the reception of a set screw (not'showm "adapted to engage and hold in place the cutter received in the socket. The hole 21 may be blocked, adjacent its lower endpby a pin 50 driven through 'a'suitably formed hole in the body'portion I9, whereby a portion of said pin is disposed within the cutter-receiving socket in blocking relation therein. I shall describe'hereinafter a modification the link ears 2| in thisv arrangement which I consider a very definite improvement thereon.

A further reduction in the number of shapes necessary for the production'of a given size of chain can be effected by selecting the end of the head l8 through which the bore is formed. That is, the'links HA", ||A"', HB", and ||B"' differ from the links HA, HA, HB, and HB, respectively, only in that the bore 30 is formed in the opposite end of the head l8 thereof.

In Fig. 5 is illustrated a forged side strap l6 which comprises a body portion 3| of a thickness susbtantially equal to one-half the thickness difference between the'link body portion l9 and and 22. Saidstrap is formed with a base flange 32 projecting from one face thereof a distance substantially equal to one-half the thickness" difference between the link body lfi' and the link flange 20. .Adjacent one end of the'opposite face of said body portion 3| there is formed a stud 33 projecting from said body facea distance substantially equal to one-half the thickness of the link ear portion 22. Adjacent'the other end of said body portion there projects from said last-mentioned face a second stud 34 of the same height. Perforations 35 and 33 are formed through said strap coaxial with the studs 33 and 34, respectively.

An ear 3? projects upwardly from the body 3| and is formed with a stud 38 of a height substantially' equal to the height of the stud 33, a perforation 39 being formed through said ear coaxial with the stud 38. A rib 40 is preferably formed adjacent the upper edge of the body 3|.

The side straps 16 are all alike; and the side straps H are also all alike, bearing an allochiral relation to said straps Hi.

When a chain is to be assembled, the stud 33 ofa strap I6 is entered in the perforation 26 of the ear 22 of each link; and the corresponding stud of a strap I1 is likewise entered in said perforation from the opposite side thereof; and a rivet is passed through the bores 35. Of course, before the straps l6 and I1 are riveted together, the stud 34 of the strap l6 and the corresponding stud of the strap I! are entered in the perforation 25 of the ear 2| of the next adjacent link; and a rivet is passed also through the'bores 36. The studs 38 of the straps I6 and I1 will then be in substantially abutting relation, and a rivet may be passed through the bores 39. The function of the ears 31 is to stiffen the chain.

As in indicated in Fig. 2, the chain trackway of a mining machine comprises a rail 4| formed with a T-slot 43 enlarged at its base as at 42. The flanges 2|! and 32 must fit within the enlargement 42, and the body portions l9 and 3| must fit within the portions 43 of the groove.

Because of the manner of forming the cutterreceiving sockets, and the manner of forming the set screw receiving bores form a chain for any given machine, using only two different forged link shapes to accomplish the function of eight cast shapes heretofore used. I have discovered that those two link shapes may not only be readily adapted to accomplish the functions of the eight castings heretofore used in the production of any one chain, but further may be used to produce chains for all of the machinesnow'on the market. Thus, instead of requiring the replacement chain manufacturer to carry in stock twenty-four different link shapes, I have made it possible for him to accomplish everything that he accomplished with those twenty four different link shapes, carrying 30, I am able to in'stock only two different types of forged link blanks. 1 I

The arrangement described herein provides an eight-position chain in a manner which is, actually, unobjectionable. However, the practical art has long been accustomed to chains made of links in which the cutter-receiving socket is formed on an axis perpendicular to the top surface of the head, and it is possible that the practical art may not, therefore, take kindly to a chain in which such sockets are formed, in some instances, on axes otherwise angularly related to the head surfaces. Obviously, it will be possible to overcome such objections while still retaining many of the advantages of my invention. Thus, four blank shapes may be used, withoutforming cutter sockets at different angles in each shape, to provide a seven-position chain, and five blank shapes may be used to form a nine-position chain.

My blank NY is originally forged with its lateral dimensions slightly larger than the lateral dimensions of the largest mining machine trackway. Of course, the rough forging must be smoothed before use and the smoothing operation reduces the lateral dimensions of the blank to values best adapted 'for cooperation with that largest trackway. In order to adapt that same blank for use in a chain to be used in connection with any one of the other machines, it is only necessary to reduce the lateral dimensions of the blank sufficiently to adapt that blank for association with the trackway of known dimensions. It happens that, in all three major machines, the lateral distance from one Vertical Wall of the portion 42 of the trackway to the adjacent vertical wall of the portion 43 of the trackway is the same. Therefore, the thickness difference between the flange portion 2|] and the body portion IQ of the link blank will remain a constant, regardless of the machine with which the chain is intended to be used and as a further consequence, the degree of projection of the flange 32 from the face of the body 3| of the side straps need not vary. To adapt an original forging to a machine of smaller dimensions, therefore, the thickness of the flange portion 20 must be reduced to a proper value, and the thickness of the body portion l9 must be equally reduced. Because of the thickness of the body portion 3| of the straps l6 and I1, it is desirable likewise to reduce the thickness of the ear portions 2| and 22 an equal amount. This requires reduction of height of the studs 33, 34, and 38 an amount equal to substantially one-half the thickness reduction of the link portions.

A feature of importance in producing my chain consists in the fact that, if it is desired to maintain constant the lateral distance from each wall of the trackway to the adjacent edge of the kerf to be cut by the machine, then the lateral distance from the adjacent surface of the link body to the point of the associated cutter must not be varied by the act of thickness reduction, particularly in view of the reversibility feature of my links. Consequently, when the thicknessreduction principle isapplied to a link having an offset head, the total reduction must be effected by machining that surface of the link opposite the offset of the head.

In Fig. 9 there is illustrated one manner in which the link may be so modified for association with various'machines. The solid line |9| represents one surface of the body portion of the link when dimensioned for use with the largest ma- 3 link blank.

chine; the dash-andwlot line I92 represents said surface when adapted for use with the intermediate machine; and the dotted line I93 represents that surface when intended for use with the smallest machine. The solid line 20I represents the flange surface when the link is intended for use with the largest machine; the dash-and-dot line 2.92 represents that surface when intended for use with the intermediate, machine; and the dotted line 293. represents that surface when intended for use With the smallest machine. The solid line 221 represents one surface of a link ear when intended for association with the largest machine; the dash-and-dot line 222 represents that surface when intended for use with the intermediate machine; and the dotted line 223 represents that surface when intended for use with the smallest machine.

However, if it is desired to maintain constant the lateral distance from the median plane of the trackway to each edge of the kerf to be cut by the machine, then the thickness reduction must be effected by removing equal amounts of metal from each of the lateral surfaces of the In Fig. 10, there is illustrated this method of modifying the link shapes for association with various machines. In, Fig. 10, the solid lines I94, I91, 294, 201', 224, and 221 represent the various opposite surfaces of the link when dimensioned for, use with the largest machine; the dash-and-dot lines I95, I98, 295, 298, 225, and 228 represent those surfaces when the link is dimensioned for use with the intermediate machine; and the dotted lines I96, I99, 206, 209, 226, and 229 represent those surfaces when intended for use with the smallest machine. It will be seen that, according to this method, onehalf the required thickness reduction is removed from each of the opposite surfaces of the link blank.

Obviously, the studs 33, 34, and 38 must be reduced. in height sufficiently so that the projection of each stud from the body portion 3| will be equal to substantially one-half the thickness of the link ear portion.

Figs. 11 and 12 represent a further form of link which may be used, in case it is desired to obviate the necessity of using cutter-receiving sockets drilled at diiferent angles in the link; such a link, indicated generally by the reference numeral 35, including a head 46 which is not offset. Such a link, of course, would carry a vertical .cutter.

In Fig. 13, I have illustrated a method of producing a substitute for the pin 59 shown in Fig. 3.

After the bore 21 and the broached grooves 28 and 29 have been formed, a bar 47, snugly fitting said grooves 28 and 29, is inserted therein from the upper end of the cutter-receiving socket. Said bar l] is provided with any desired means for limiting its. degree of penetration into the socket, a head 48 being illustrated as such a means. The bar 4.! is designed and dimensioned so that the end 69 thereof will, when the bar has been fully introduced into the socket, lie in the plane which is desirably occupied by the bottom end of the cutter which is. adapted to be associated with the link. Thereupon, a Weld rod 5! is introduced from the opposite end of the socket 27, and is brought into contact with a wall of the socket to deposit a shoulder or abutment 52 of metal thereagainst. The metal so deposited, will, of course, be welded integrally to the link body; and if the bar 41 is made of copper, the metal so deposited will not be welded to the bar. Thus, the bar 41' may be readily withdrawn from the socket after the abutment 52 has been deposited.

The obvious simplicity of the above-described methodof producing a stop for cutters, as compared with the provision of a stop such as the pin 59, will demonstrate the importance of this improvement; and it will be evident that dislodging or shearing olT often encountered with the usual stop pins will be eliminated by my stop formed of solid metal deposited as an integral part of the link.

I claim as my invention:

1. The method of making a mining machine cutter chain link which includes the steps of forging a link blank shaped to provide a head and a plurality of portions of different thicknesses, each one of said last-named portions having at least one surface parallel to at least one surface of each other one of said last-named portions, and machining certain of said parallel surfaces to reduce the thicknesses of certain of said last-named portions to adapt said link for use with any selected one of various mining machines.

2. The method of making a mining machine cutter chain link which includes the steps of forging a link blank shaped to provide a head, a main body portion, a pair of oppositely longitudinally projecting ears of less lateral extentv than said main body portion, and a pair of oppositely laterally projecting flanges of greater lateral extent than said main body portion, forming an aperture through each of said ears, forming a bit-receiving socket in said head, and reducing the lateral extent of said ears, said body portion, and said flanges to adapt said link to. any selected one ,of a plurality of mining machines.

3. The method of making a mining machine cutter chain link which includes the steps of forging a link blank shaped to provide a head, a main body portion, a pair of oppositely longitudinally projecting ears of less lateral extent than said main body portion, and a pair of oppositely laterally projecting flanges of greater lateral extent than said main body portion, forming an aperture through each of said ears, forming a bit-receiving socketin said head and body portion, forming a threaded socket from one longitudinal end of said head and opening into said bit-receiving socket, and reducing the lateral extent of said ears, said body portion, and said flanges to. adapt said link to any selected one of a plurality of mining machines.

4. The methodv of making a mining machine cutter chain link which includes the steps of forging a blank including a. head and a body, and drilling a hole through said head and body, said hole opening through the upper surface of said head and having its axis disposed on any one of a plurality of predeterminedangles to the. vertical.

5. The method of making a mining machine cutter chain link which includes the steps of forginga blank. including a head and a body, drilling a hole through said head and body, said hole opening through the upper surface of said head and having its axis disposed on any one of a plurality of predetermined angles to the vertical, and breaching rectangular groovesat longitudinally opposite sides. of said hole. 7

6. The method of making a mining machine cutter chain link which includes the steps of forging a blank, including a head and a body, drilling a hole through said head and body, said hole opening through the upper surface of said head and having its axis disposed on any one of a plurality of predetermined angles to the vertical, broaching rectangular grooves at longitudi- 'nally opposite sides of said hole, and forming a tion into said hole at a point remote from said head, to form a stop for a cutter received in said first-named hole.

8. The method of making mining machine cutter chains for use with any selected one of a plurality of mining machines, which includes the steps of forging a plurality of link blanks, each comprising a head, a main body, a lateral flange adjacent the base of said main body, and a pair of terminal ears, said body being of less thickness than said flange and said ears being of less thickness than said body, perforating said ears, forging a plurality of side straps, two for each link, each comprising a body portion of a thickness substantially equal to one-half the thickness difference between said link body and said ears, a flange projecting from said strap body a distance substantially equal to one-half the thickness difference between said link body and said link flange, and a pair of studs, one adjacent each end of said strap body and projecting therefrom a distance substantially equal to one-half the thickness of said ears, machining said link flanges to reduce the thickness thereof to adapt said links to the selected machine, machining said link ears to reduce the thickness thereof an equal amount, machining said strap studs to reduce the thickness thereof by one-half such amount, and associating a pair of straps with each two adjacent links by entering said strap studs in said link ear perforations.

9. The method of making mining machine cutter chains for use with any selected one of a plurality of mining machines, which includes the steps of forging a plurality of link blanks, each comprising a head, a main body, a lateral flange adjacent the base of said main body, and a pair of terminal ears, said body being of less thickness than said flange and said ears being of less thickness than said body, perforating said ears, forging a plurality of side straps, two for each link, each comprising a body portion of a thickness substantially equal to one-half the thickness difference between said link body and said ears, a flange projecting from said strap body a distance substantially equal to one-half the thickness difference between said link body and said link flange, and a pair of studs, one adjacent each end of said strap body and projecting therefrom a distance substantially equal to onehalf the thickness of said ears, machining one surface of each link body, link flange, and link ear, to reduce the thickness thereof in equal amounts, machining said strap studs to reduce the thickness thereof by one-half such amount to'adapt said links and straps to the selected machine, and associating a pair of straps with each two adjacent links by entering said strap studs in said link ear perforations.

10. The method of making a mining machine lcutter chain link which includes the steps of producing a link formed with a cutter-receiving socket open at both ends, inserting into one end of said socket a copper bar, and inserting into the other end of said socket a weldingrod to deposit a gob of metal on a wall of said socket against said bar.

FRANK L. FULKE. 

